Resistive and capacitive touch screens were developed for LCD displays as one form of user interface, i.e., a graphical interface. These touch screens are appropriate for large array applications but are expensive to manufacture. Touch screens are cost effective on “per pixel” basis when the array is large. For discrete “button” applications, however, touch screens tend to be costly compared with mechanical buttons. Prior art HMI suffer from following limitations:                A capacitive touch HMI detects a permittivity increase due to the water content in the human body. They often fail with gloves on. If tuned for high sensitivity, spurious detections of water-containing or metallic objects passing by can be problematic.        Resistive touch technology depends on conductive elements separated by a thin layer of polymer. The conductive element may form a resistive leakage path after repeated use or after extended exposure to pressure and/or humidity. Wear-out of the conductive elements after repeated contacts can also result in sporadic open circuit under use.        Mechanical buttons, similarly, also suffer wear and tear over repeated use. In addition, they generally require holes in the control panel which allow water or contaminants to enter. This results in additional reliability concerns beyond the wear and tear due to movement.        In addition to robustness concerns, none of the preceding HMI method could sense the force or speed of interaction (contact). An HMI that can correlate human sense of force and speed of contact, i.e., impact, will enhance user experience tremendously.        